Metro-North is undergoing a systemwide inspection of the joint bars that link rail together in the wake of a federal safety probe looking into whether repairs made in April to the steel fastener had a role in the collision of two trains in Connecticut last week.

The preliminary finding Friday by the National Transportation Safety Board didn't directly pin blame for the May 17 crash on the cracked joint bar in the area of the collision that was repaired last month. However, agency officials indicated that it has become an early focus of their probe and said that Metro-North is inspecting the joint bars in use elsewhere in the commuter rail system.

The NTSB's announcement came as the agency wrapped up its on-scene investigation of the rush-hour derailment of an eastbound Metro-North train near Bridgeport that injured 72 people, including commuter rail workers. The full investigation is expected to take six months.

The New Haven-bound train derailed shortly after 6 p.m., came to a full stop, and was sideswiped 20 seconds later by a train bound for Manhattan's Grand Central Terminal, the NTSB said Friday.

Investigators said the engineer on the derailed train, who has not been identified, has told them that he noticed "an unusual condition on the track as he approached the Interstate 95 overpass."

The train can typically ride over the damage as long as the rail line beneath it stays intact, he explained.

Additionally, the head of the union representing Metro-North track workers, told Newsday Monday that track in the area of the crash was inspected on May 15. At the time, there was nothing to indicate to two track inspectors that the rail was damaged, according to Chris Silvera, the secretary-treasurer of Local 808 of the International Brotherhood of Teamsters.

The NTSB probe revealed that the engineer of the Manhattan-bound train hit the emergency brakes before striking the derailed train, a finding first reported by Newsday on Tuesday.

"If he was going full speed, forget about it," said Anthony Bottalico, the general chairman of the Association of Commuter Rail Employees.

The eastbound train was going 70 mph before it came to a stop.

During the weeklong probe, the NTSB collected photos, recordings and inspection reports and interviewed Metro-North employees who were aboard both trains when the collision occurred.

Conductors and engineers aboard both trains have hired a personal injury lawyer, George Cahill, and are considering filing lawsuits, accusing the nation's busiest commuter rail of negligence for failing to properly repair damaged track in the weeks leading up to the crash, Newsday reported Tuesday.